IEC standards for individual monitoring of ionising radiation

This paper presents IEC/SC 45B 'Radiation protection instrumentation' and its standards for individual monitoring of ionising radiation: IEC 61526 Ed. 3 for active personal dosemeters and IEC 62387-1 for passive integrating dosimetry systems. The transposition of these standards as CENELEC (European) standards is also discussed together with the collaboration between IEC/SC 45B and ISO/TC 85/SC 2.     

New concept of IEC standards for radiation protection dosemeters

The International Electrotechnical Commission (IEC) develops new standards for radiation protection dosemeters which follow a new concept. They are much more flexible in detail, but still ensure the same measurement quality. They are, for example, no longer specific for the detector type, but rather specific for the measurement task, e.g. for individual monitoring with active direct-reading instruments. Another example is that they are flexible with respect to the ranges of influence quantities. The conceptual changes are described in this paper, together with the advantages this new concept provides for manufacturers, users and legislators.     

Results of radiation protection programmes on mammography

In this paper, we present the results of mammography quality control tests related to the work with Portuguese mammography equipment, either in conventional or in digital mammography computed radiography, showing the main differences in the tested equipments. Quality control in mammography is a very special area of quality control in radiology, which demands relatively high knowledge on physics. Digital imaging is changing the standards of the radiographic imaging. Regarding mammography, this is yet a controversial issue owing to some limitations of the digital detectors, like the resolution for instance. A complete set of results regarding radiation protection of the patients submitted to mammography diagnosis is presented. A discussion of the quality image parameters and its interpretation in conventional and digital mammography is presented. In conclusion, we present a sample of results that can be considered as characteristics of mammography equipment in Portugal.     

Normalization properties for Shallow TRS and Innermost Rewriting

Computation with a term rewrite system (TRS) consists in the application of rules from a given starting term until a normal form is reached. Two natural questions arise from this definition: whether all terms can reach at least one normal form (weak normalization property), and whether all terms can reach at most one normal form (unique normalization property). Innermost rewriting is one of the most studied and used strategies for rewriting, since it corresponds to the “call by value” computation of programming languages. Henceforth, it is meaningful to study whether weak and unique normalization are indeed decidable for a significant class of TRS with the use of the innermost strategy. In this paper we study weak and unique normalization for shallow TRS and innermost rewriting. We show decidability of unique normalization in polynomial time, and decidability of weak normalization in doubly exponential time. We obtain an exptime-hardness proof for the latter case. Nevertheless, when a TRS satisfies the unique normalization property, we conclude the decidability of the weak normalization property in polynomial time, too. Hence, whether all terms reach one and only one normal form is decidable in polynomial time. All of these results are obtained assuming that the maximum arity of the signature is fixed for the problem, which is a usual assumption.     

Air kerma to Hp(3) conversion coefficients for a new cylinder phantom for photon reference radiation qualities

The International Organization for Standardization (ISO) has issued a standard series on photon reference radiation qualities (ISO 4037). In this series, no conversion coefficients are contained for the quantity personal dose equivalent at a 3 mm depth, H(p)(3). In the past, for this quantity, a slab phantom was recommended as a calibration phantom; however, a cylinder phantom much better approximates the shape of a human head than a slab phantom. Therefore, in this work, the conversion coefficients from air kerma to H(p)(3) for the cylinder phantom are supplied for X- and gamma radiation qualities defined in ISO 4037.     

X reference radiation qualities produced with tube voltages above 300 kV for the calibration and testing of dosemeters

In the international standard ISO 4037-1, only X reference radiation qualities produced with tube voltages of up to 300 kV and with mean photon energies of lower than 250 keV are defined. Higher energy reference photon fields are given with a mean energy only from 662 keV (S-Cs) upwards. To close this energy gap, four new X radiation qualities, produced with tube voltages of 350 kV and 400 kV, were realised. The filtration of two of these qualities-called N-350 and N-400-was chosen in such a way that they agree with the specifications of the narrow-spectrum series (N-series) defined in ISO 4037-1. The other qualities which have been created-called H-350 and H-400-can be assigned to the high air-kerma rate series (H-series). The fluence spectra of these qualities were measured by using X-ray spectrometry. The values of 23 characteristic parameters were determined and compared with the ISO specifications for X-ray reference fields.     

Measurement of the detective quantum efficiency (DQE) of digital X-ray detectors according to the novel standard IEC 62220-1

A mobile measurement facility which complies with IEC 62220-1 has been set up to determine the detective quantum efficiency (DQE) of digital X-ray detector systems. Exemplary measurements were performed for two similar CR detector systems, a CsI-based indirect detector and an Se-based direct detector. The standardised radiation quality RQA 5 was applied for measurement and for three of these systems RQA 9 was also applied. A pronounced dependence of DQE on radiation quality was observed for the direct detector, where the DQEs for RQA 5 and RQA 9 differ by a factor of approximately 2. The uncertainty (95% confidence interval) associated with the measured DQE values is within 0.01 and 0.04 depending on, for example, the spatial frequency. Thus, it has been demonstrated that the DQE can be measured accurately and reliably with the accuracy required by the international standard IEC 62220-1. It is now possible to objectively measure and compare DQE values of digital X-ray detector systems.     

Calibration of dosemeters used in mammography with different X ray qualities: EUROMET project no. 526

The effect of different X ray radiation qualities on the calibration of mammographic dosemeters was investigated within the framework of a EUROMET (European Collaboration in Measurement Standards) project. The calibration coefficients for two ionization chambers and two semiconductor detectors were established in 13 dosimetry calibration laboratories for radiation qualities used in mammography. They were compared with coefficients for other radiation qualities, including those defined in ISO 4037-1, with first half value layers in the mammographic range. The results indicate that the choice of the radiation quality is not crucial for instruments with a small energy dependence of the response. However, the radiation quality has to be chosen carefully if instruments with a marked dependence of their response to the radiation energy are calibrated.     

Consideration on calibration and correction factors of an Hp10 chamber for different radiation qualities and angles of incidence

This paper presents the characterisation performed at IRSN (France) of an H(p)(10) chamber in terms of calibration coefficient and correction factors for the radiation qualities of ISO narrow spectrum series. The chamber response, expressed in H(p)(10) using conversion coefficients h(p)(K)(10; N, alpha) listed in ISO 4037-3 in the energy range from 30 to 1250 keV and for angles of incidence between 0 and 70 degrees, was found to be within approximately 10%. However, for photon energies <30 keV, an overresponse of the chamber that could reach 100% was observed. Nevertheless, this overresponse was reduced to 25% using the conversion coefficients estimated at Physikalisch-Technische Bundesanstalt (PTB). This implies that the X-ray spectra produced by the IRSN X-ray units are very similar to those produced by PTB, both containing a little bit more high-energy photons than the spectra used in ISO 4037-3. The dose rate dependence of the chamber tested by gamma radiation from (60)Co sources was found to be within 2% in the range of 0.3 mSv h(-1) to 1 Sv h(-1). The H(p)(10) chamber can measure directly the conventional true value of H(p)(10) after calibration by a reference laboratory, and can be used for transferring H(p)(10) reference quantities from a reference laboratory.     

Energy and directional response for the Harshaw dosemeter holders 8814 and 8891, and its effect on the appropriate radiation qualities for absolute calibration

The personal dosimetry laboratory at the Norwegian radiation protection authority utilises a two-element dosemeter card for measuring Hp(10) and Hp(0.07), in a Harshaw dosemeter holder type 8814. Energy and directional responses for photons and betas for this holder have been assessed, as well as for the new Harshaw holder type 8891. The energy response characteristics for the 12-1250 keV photon energy range, in terms of TL output per unit Hp(10) and Hp(0.07) have been evaluated. The maximum over-response to under-response ratio for the Hp(10) element was found to be 1.46 for the new type 8891 holder, as compared to 1.55 for the older type 8814. The new holder also displays a more favourable directional response for this element. For the Hp(0.07) element, no significant differences with regard to energy or directional responses were found. Selecting radiation energy for absolute calibration of the Hp(10) and Hp(0.07) elements are discussed.     

The recommended energy dependences of the sensitivity of photon radiation emergency dosimeters according to the NRB-99 standard

The recommended energy dependences of the sensitivity of emergency dosimeters are calculated for different irradiation geometries in the photon energy range of 10 keV–10 MeV. These serve to estimate the levels of radiation for which, according to the NRB-99 standard, either urgent action or action for chronic exposure is necessary. __________ Translated from Izmeritel’naya Tekhnika, No. 11, pp. 52–56, November, 2007.     

Measurement of the radiation dose and assessment of the risk in mammography screening for early detection of cancer of the breast, in Israel

The mean glandular doses to samples of women attending for mammographic screening are measured routinely at screening centres in Israel. As at present, no detailed and systematic data have been collected regarding the average glandular dose in mammography screening procedures carried out in Israel for the last 20 y. Especially data are lacking related to the glandular dose (GD) involved in mammography with the new digital mammography systems. In this work, partial results of the measurements are presented to asses the radiation dose to the breast and to the glandular tissue within the Israeli national mammography programme updated to year 2009.     

IEC网上书店Webstore的主要特色

作为世界三大标准机构之一的IEC，其网上书店很有特色。IEC网店（http：／／Webstore．iec．ch）所销售的标准，不仅有传统的纸本，还有PDF、数据库以及光碟等多种电子版。除了其页面简洁和功能全面的特点之外，IEC网店的最大特色是其可以提供从1906年创办以来的所有标准文本，     

China contributes to the publication of a new IEC standard

正The first international standard on receiver equipment testing of BeiDou navigation satellite system was officially published by IEC on March 11,2020.The standard is the result of three years' research and exploration by several     

浅议ISO／IEC17025与ISO／IEC17020的差异及有关问题探讨

0 引言 实验室认可在我国已实施10多年了,从ISO国际导则25过渡到ISO/IEC 17025∶ 2005<检测和校准实验室能力的通用要求>和ISO/ IEC 17020∶ 1998<各类检查机构能力的通用要求>,对于推动我国实验室认可工作,规范实验室管理和技术要求的建设,起到了积极作用并取得了良好效果.     

Adaptation of the present concept of dosimetric radiation protection quantities for external radiation to radiation protection practice

The present concept of dosimetric radiation protection quantities for external radiation is reviewed. For everyday application of the concept some adaptations are recommended. The check of the compliance with dose limits should be performed either by the comparison with values of the respective operational quantities directly or by the calculation of the protection quantity by means of the operational quantity, the appertaining conversion coefficient and additional information of the radiation field. Only four operational quantities are regarded to be sufficient for most applications in radiation protection practice. The term equivalent should be used in the connection dose equivalent only. Proposals are made for names of frequently used operational quantities which are denoted up to now by symbols only.     

参加IEC/TC 105年会情况介绍

在国家标准委高新部和国际部的大力支持下,今年由中国电器工业协会组团(成员包括中科院大连化物所和大连新源动力股份有限公司的专家)参加了国际电工委员会燃料电池技术委员会(IEC/TC105)的年会,会议期间应邀访问了日本电机工业会(JEMA),笔者有幸参加此次会议,现将有关情况介绍如下:一、IEC/TC105进展情况介绍工作范围:制定出适用于燃料电池技术的国际标准包括的燃料电池技术有:固定式燃料电池、运输用燃料电池(如驱动和辅助动力发电系统)、便携式燃料电池、微型燃料电池等。成员:目前TC105有16个正式成员国,其中除了美国、加拿大和…     

A New Alternative for the Input-Voltage Adaptor of the IEC Flickermeter

In this paper, we present a study of the linearity of the International Electrotechnical Commission (IEC) 61000-4-15 flickermeter when subject to rectangular fluctuations of different amplitude. We show, both analytically and through simulation, how the scaling in block 1 causes the nonlinear response of the flickermeter. While the standard proposes scaling methods based on the rms value of the input voltage, we introduce an alternative method based on the mean value of the rectified input voltage. The measured P_st using the new scaling method has a linear relationship to the amplitude of the voltage fluctuations.     

IEC standards for radiological equipment: issues for the industry and for end users

The International Electrotechnical Commission (IEC) is a global standard organisation established under the Presidency of Lord Kelvin in 1906. All medical equipment standards in IEC are dealt with by Technical Committee (TC) 62, and within this, Medical Imaging Equipment Standards are developed under the guidance of Subcommittee (SC) 62B. In September 2005, a special meeting of a Steering Group of IEC SC 62B was held to review X-ray standards and to identify an approach to new standards in this field. The agenda for new standards arising from this was definitively established and consolidated, concentrating on whole systems, with the aspiration of returning later to acceptance test and QA standards. A liaison was also established between SC 62B and SENTINEL. In addition, it was decided to review SC 62B's liaisons with the International Atomic Energy Agency and International Commission on Radiological Protection and some national/international professional bodies.     

Investigation of the structure parameters according to the solidification parameters for pivalic acid

Pivalic acid was unidirectionally solidified in a temperature gradient stage. The microstructure parameters; the primary dendrite arm spacing, ₁, secondary dendrite arm spacing, ₂, dendrite tip radius, R and mushy zone depth, d, were measured for five different growth rates in a constant temperature gradient, G and for five different temperature gradients in a constant growth rate, V. The depending of the microstructure parameters to the solidification parameters (V, G and GV) for pivalic acid were determined by linear regression analyze. The stability constant, ^* was calculated by using the experimental values of R and V. The results were compared with the previous works.